When does the final calculation happen then, at file save/export? Will be unexpected. Or does it end up in the final format? That's going to be a nightmare, because then you can't use GIMP to redact data anymore.
That's up to you. Right now filters work the same way - you can merge them automatically on creation, merge them at some point while working, or merge them on export. For formats like PSD, we'll eventually add the option to export as non-destructive filters as well.
We don't want to take away choices - we just want to add more options for people's workflows.
